Gripping devices



C. C. BROWN GRIPPING DEVICES July 9, 1963 Filed 001'.. 25,' 1958 3Sheets-Sheet 1 all! DI f r C. C. BROWN GRIPPING DEVICES July 9, 1963 3Sheets-Sheet 2 Filed Oct. 23, 1958 CICERO C'. BROWN INVENTOR. mCL/Lm/ ggrada/141A 4TTORNEYS C. C. BROWN GRIPPING DEVICES July 9, 1963 5Sheets-Sheet 3 Filed 001;. 23, 1958 c/c'E/Po c: feow/y INVENTOR.

IAM 67' ILJGMA 7n, hl' M Arme/VIE Ys 3,096,824 GRIPPING DEVICES CiceroC. Brown, 8490 Katy Road, Houston, Tex. Filed Oct. 23, 1953, Ser. No.769,189 17 Claims. (Cl. 16d-210) This invention relates to new anduseful improvements in gripping devices.

r[The invention is particularly adapted for use with well tools andapparatus, such as well packers, wherein it is necessary to hold oneportion of the tool against movement while another portion thereof ismoved, as, for example, in setting `and releasing a well packer.

The usual type of device for performing this function is generally knownas a friction shoe or friction spring assembly in which a frictionalcontact between a shoe element or spring and the wall of the casing orwell bore is depended upon to hold a desired part against movement. Ifthe frictional contact is strong enough to accomplish the purpose ofholding the assembly, then difficulty is experienced in lowering thetool into the well because of the excessive frictional resistance; onthe other hand, if the frictional resistance to lowering is reduced byreducing the force of frictional contact, no assurance is had thatproper operation of the tool will be accomplished when the lowering pipeis manipulated.

It is, therefore, one object of this invention to provide an improvedgripping device which lmay be substituted for .the usual friction shoeor spring assembly of a well tool and which overcomes Iall of thedisadvantages thereof in that it may be readily lowered without offeringany resistance to such lowering and yet may be easily actuated topositively and firmly engage the wall of the pipe or bore when it isdesired to lock a portion of the tool on which it is mounted againstmovement.

An important object is to provide an improved gripping device havingwall gripping elements which are displaced outwardly into grippingposition by a simple manipulation of the member upon which the device ismounted, the device including a cam-type actuator which exerts apositive outward force upon the elements to assure their movement intotight gripping position.

Still another object is to provide a gripping device, of the characterdescribed, wherein arcuate gripping elements are mounted upon `a supportin such manner that said gripping elements normally engage the wall ofthe well pipe or bore with relatively light frictional contact, saidelements being movable into tight gripping position by a rotation of thesupport on which the device is mounted and being maintained in such iirmgripping position until the support is again manipulated.

A further object is to provide a gripping device which may be combinedwith a well packer or other tool or which, if desired, may merely mountupon a well pipe to function vas an anchor to lock said pipe againstmovement in a Well bore.

The construction designed to carry out the invention will be hereinafterdescribed, together with `other features thereof. Y

The invention will be more readily understood from a reading of thefollowing specilication and by reference to the accompanying drawings,forming a part thereof, wherein an example of the invention is shown andwherein: l

FIGURE 1 is a view, partly in section and partly in elevation of agripping device constructed in accordance with the invention` andshowing said device combined with the anchoring means of a well packer,said device being in a normal or non-gripping position;

FIGURE 2 is a similar view with the gripping device actuated and thepacker in set position;

FIGURES 3, 4 and 5 are horizontal cross-sectional 3,096,824 PatentedJuly 9, 1963 views, taken on the lines 3 3, 4 4 and 5 5, respectively,of FIGURE l;

FIGURE 6 is a horizontal cross-sectional view .taken on line 6 6 ofFIGURE 1 with the gripping elements of the device in a normal,non-gripping position;

FIGURE 7 is a similar view, taken on the line 7 7 of FIGURE 2 with ltheelements in firm gripping position;

FIGURE 8 is a longitudinal sectional view of the gripping device mountedupon a Well pipe for anchoring said pipe within a well bore;

FIGURE 9 is a horizontal cross-sectional View similar to FIGURE 6 butillustrating `a gripping device having three gripping elements;

FIGURE 10 is ya horizontal cross-sectional view similar to FIGURE 7 butillustrating a gripping device having three gripping elements; and

FIGURE 1l is a partial sectional View similar to FIG- URE 1 butillustrating the gripping device connected with the expander cone ratherthan the gripping slips of Vthe Well packer.

In the drawings the improved gripping device which is generallyindicated by the letter A has been shown in FIGURES 1 and 2 as used witha well packer; in FIG- URE 8 the device A is merely applied to a pipe orsupport for the purpose of lanchoring the same within another pipe, suchas a well casing. It is pointed out that the illustrations of theparticular use of the invention are exemplary only and, as willhereinafter appear, the device may be employed in any environment whereit is desired to maintain a member against movement Within a pipe `orWell bore.

Referring to FIGURES 1 and 2, the gripping device A of this invention ismounted at the lower end of a Well packer P. The packer may be of anydesired construction but as shown includes a central tubular support ormandrel having its upper end connected through `a coupling 11 with awell tubing or lowering pipe 12. An annular flexible packing element 13surrounds the mandrel and below said mandrel an annular slip expander orcone 14 is mounted; the cone may be limited against downward movement onthe mandrel by means of a shoulder 15.

Arcuate wall engaging members 16, which are shown in the form of theusual gripping slips, surround the expander cone 14 and also surroundthe mandrel 10 as is clearly illustrated in FIGURE l. The vrear surfacesof the members or slips 16 are provided with projections 17 which fitwithin retaining grooves 1S in the cone whereby outward displacement ofthe slips from the cone or eX- pander is prevented. As is usual ingripping slip assemblies of this character, the relative movement of thecone 14 with respect to the gripping slips 16 will, due to the inclinedco-acting surfaces of these parts, cause a radially outward movement ofthe slips whereby said slips may engage the wall of the well casing C.When the slips are in their lowered position with respect to the cone(FIG- URE `1), said slips are retracted, but when moved upwardly alongthe surface of the cone (FIGURE 2), said slips are engaged.

As is well known in the well packer art, the gripping slips are normallyin their retracted position While the packer is lowered within the wellcasing. Upon reaching the desired position at which the packer is to beset, it is necessary that the slips 16 be released for upward movementrelative to the expander or cone 14 and the usual type of packer employsa friction spring assembly which is connected with the slips and whichis also connected to the mandrel through a J-slot connection. Thedisadvantages of the usual friction spring assembly are that if thesprings are strong enough to support the slip assembly when it isdesired to set the packer, they present an objectionable resistance tolowering. If made so as to engage the wall only with a light frictionalresistance during lowering, the friction springs may not be sufficientto support the slips and assure proper setting.

In place of the usual friction spring assembly, the gri ping device A ismounted on the lower end of the mandrel or support 10. f course, thedevice A could include its own mandrel or support which would havethreaded connection with and form a continuation of the packer support10. Sur-rounding the support is a tubular sleeve 2d having an enlargedcollar 2d at its lower end. The collar 21 is secured to the lower end ofthe sleeve 2i) by radially extending pins 22 (FIGURE 5) which arethreaded into the collar and which extend through openings 23 in thesleeve 20.

The upper end of the tubular sleeve 2o is formed with a lateral orannular ange 24 whi-ch preferably has the same radial projection as thecollar 21. As shown in FIGURES l and 2, the lower surface of the ange 24is spaced from the collar 21 and gripping elements G, which will behereinafter described in detail, are disposed within this space.

For connecting the tubular sleeve 20 of the gripping device A with thegripping slips 16, the flange 24 is formed with upwardly connecting lugs25 which are engageable within recesses 26 in the lower external portionof the gripping slips 16. It is thus obvious that the tubular sleeve 20and its associated parts have a direct connection with the grippingslips 16 and when the sleeve 2o is held stationary, the slips 16 arealso held stationary. Although the lugs 25 and recesses 26 provide asimple manner of attachment between the device A and said slips, anyother suitable means may be employed.

For attaching the tubular sleeve 20 of the gripping device A to themandrel or support, the inner ends of the pins 22, which, as explained,are secured to the collar and sleeve, are adapted to engage withinJ-slots 27. The J- slots are diametrically opposed and are formed in theexternal surface of the mandrel or support 1%'. When the pins 22 are inthe lateral portions 27a of the J-slots 27, upward movement `of thesleeve 20 and of the gripping slips 16 connected therewith with respectto the mandrel or support is prevented. Therefore, at this time thegripping slips 16 can not mov-e upwardly with respect to the expander14, the parts being in the position shown in FIGURE 1.

When the support or mandrel is rotated by means of the tubing orlowering pipe 12, the J-slots 27 may turn with respect to the pins 22 sothat said pins may align with the vertical portion 27b of the J-slots27. Thereafter, the support or mandrel 10, which also carries theexpander 14, may be moved downwardly with respect to the tubular sleeve2t) of the device A and with respect to the gripping slips 16 connectedtherewith. As the expander moves downwardly, the gripping slips '16 willbe moved outwardly into gripping engagement with the pipe as shown inFIGURE 2 and thereafter the imposition of weight of the support pipeupon the flexible packing element 13 will expand the same into sealingposition.

In the particular packer shown, upper auxiliary holddown means 28 aremounted in the coupling member 11. These means are in the form ofholddown buttons 23 and each is mounted within a recess 29, The rearsurface of each button is exposed through ia port 29a to the pressurewithin the bore of the support. A coil spring 31 normally holds eachbutton 'in retracted position until the pressure acting against thebutton is sufficient to urge the same into gripping position.

From the foregoing it will be evident that when the packer is to be set,the support ll` having the J-slots 27 therein must undergo a rotationwith respect to the gripping device A; also, it is necessary that thegripping slips 16 be held stationary within the well casing C to permitthe subsequent downward movement of the support and the expander cone 14with respect to the slips. To assure that the gripping device A willhold the slips against movement, the gripping elements G are provided.Each gripping element is in the form of a generally semicircular shoe 30(FIGURES 6- and 7), which substantially encircles one-half of thetubular sleeve 2t). The lower end of each shoe has a depending iiange 31which coacts` with an upstanding iiange 21a on the collar 21 while theupper end of the shoe has a fange 32 co-acting with a dependingprojection 24a on the ange 24; it will be evident that the flanges 31and 32 limit the outward movement of the shoe with respect to thetubular sleeve.

Each arcuate shoe 3) has an enlarged contact portion 33 and the centrallouter surface 33a of this portion is substantially smooth to provide anon-gripping area which frictionally engages the wall of the well casingC. Gripping surfaces such as gripping teeth 3317 and `33C are formed .oneach side of the non-gripping surface 33a in the manner illustrated andIeach set of gripping teeth is spaced from the wall of the casing C whenthe smooth non-gripping surface is contacting said casing which is theposition shown in FIGURE 6. Normally the shoes are placed around thesleeve 20 and are urged outwardly so that their respective non-grippingsurfaces 33a slidably engage the wall of the well casing by coil springs34, the ends of said springs being mounted within recesses 35 in thefree ends of each shoe. Said free ends of the shoes are spaced lfromeach other to allow independent movement with respect to each other. `Itis pointed out that the springs 34 are relatively weak and are onlysufficient to urge the non-gripping surfaces of the shoes 30 intocontact with the wall of the pipe with a relatively light friction. Thefrictional force should only be sufficient to prevent the shoe elements30 from rotating. This light frictional contact permits the device A tobe lowered downwardly through the well casing without presenting anygreat resistance to such lowering.

For the purpose `of effecting a gripping engagement of each shoe 30 withrespect to the wall of the casing in order to assure that the grippingslips 16 connected with the device will be held against movement, eachgripping shoe has the internal surface of its enlarged portion 33inclined to form cam surfaces in the manner indicated at 36 and 37.These inclined cam surfaces are adapted to co-act with a cani-typeprojection 38 which is provided on the external surface of the sleeve20. As is clearly shown in FIGURE 6, two diametrically opposedprojections 38 are provided and these projections are normally locatedas shown in this figure with respect to the inclined surfaces 36 and 37of the arcuate shoes 30.

In the operation of the gripping device the parts are in the positionshown in FIGURES 1 and 6. At this time the pins 22, which are carried bythe collar 21 and sleeve 20 of the device, are engaged in the lateralportion 27a of the J-slots 27. The light coil springs 34 are urging thearcuate gripping elements or shoes `30` radially outwardly and aremaintaining the smooth non-gripping surface 33a of each shoe in lightfrictional contact with the wall of the well casing; at this time thegripping surfaces 33b and 33e are in spaced relationship to the wall ofthe well casing C. Thus, the well packer P may be lowered downwardlythrough the well casing to the point at which it is to be set andgripping slips 116- 0f the packer, which are connected with the deviceA, can not move to a set position.

When the point at which the packer is to be set is reached, the supportor mandrel 10` is rotated to the right by means of the lowering pipe orwell tubing 12. Such rotation will cause the cam projections 38 on thesleeve 20 to move into contact with the inclined surface 37 off therespective shoes 30 in the manner illustrated in FIG- URE 7. As each camcontacts the adjacent inclined surface 37 of the shoe, the shoe willundergo a slight rocking motion in a circumferential path and this willcause the teeth 3317 of each shoe to firmly engage the wall of the wellcasing. The rocking action is effected by reason of the initial slightclearance or spacing between the gripping surfaces 33b and 33e and theywall of the casing C by reason of the angle of contact between thecam-type projection and the cam surface, which latter applies a radialforce resulting in a combined rocking and radial shifting of the shoesuflicient to engage the gripping surface 331? with the pipe Wall. Therocking motion is assured because the smooth nongripping surface 33a isin contact with the wall at the time force is first applied so that, ineffect, said smooth surface provides the pivotal point about whichrocking can take place.

Contact of the gripping teeth l33b with the casing sets up a irrngripping engagement between the shoe and the casing and, obviously,since the cam projections 38 are formed on the sleeve 20, lfurtherrotation of the sleeve will be impossible. The sleeve 20 is thus iirmlyanchored against any longitudinal or further rotational movement. Theinner mandrel l is then lifted slightly so that the pins 22 (connectedto the sleeve 20 and collar` 21) are located at or near the bottom ofthe lateral portions 27a of the J-slot 27 (formed in the mandrel i10)rIhe pins 22 are thus clear of the depending portion or lip on themandrel 10 formed between the portions 27a and the relatively longervertical portions 27b of the J-slot, and continued right-hand rotationof the mandrel 10 while the pins 22 remain anchored or stationary willmove the portions 27h of each J-slot 27 into alignment with theirrespective pins 22. Thereafter, the support and its associated partsincluding the expander 14 may be lowered relative to the anchored deviceA and relative to the gripping slips 16 which are connected therewith.The positive engagement of the gripping elements or shoes 30 with thewall off the well casing will assure that the pins 22 may be properlyaligned with the vertical portion 2712 of the J-slots and will furtherassure that the gripping slips 16 will remain stationary While theexpander 14 is lowered with respect thereto. Of course, after the slips16 are set, the weight of the lowering pipe 12 is imposed upon thepacking element to set said packer and the device A has no furtherfunction. Thereafter, the support could be rotated back to the left toreturn the shoes to the position of FIGURE 6 although this is notessential since the shoes may remain in the position of FIGURE 7 so longas the packer remains set.

When it is desired to remove the packer, the support or mandrel islifted and then rotated to the left to return the connecting pins 22into the lateral portions of the slots 27 and, of course, at that timethe cam projections 3S on the sleeve return to the position of FIGURE 6whereby the only frictional contact between the shoes 30 and the casingwall is that produced by the relatively light springs 35.

From the foregoing it will be seen that a simple and effective device isprovided which may be lowered through the well pipe with a minimum offrictional contact with the wall of the pipe whereby the device will notintertere with the lowering operation. However, when it is desired thata firm engagement between the shoes 30 and the pipe wall be had, it ispossible to actuate the shoes through the cam-type projections 38 andmove said shoes into positive gripping engagement. This assures that theJ-slot may be properly manipulated and that the slips will be maintainedstationary to permit positive setting of the packer. It has been foundthat two generally semicircular shoe elements will be sufficient but itis within the scope of this invention to provide a greater number ofgripping shoes as, for example, three or four segmental shoes may beprovided and in such case each shoe would be actuated by its owncam-type projection. FIG- URES 9 and 1G illustrate the device Aincluding three gripping elements 30 and the three coacting cam-typeprojections 3S. Also, although the device A has been shown and describedas connected with the gripping slips 16, said device could be connectedwith an expander cone as illustrated in FIGURE 11; in such arrangementthe slips 16 are carried by the support or mandrel and would 6 be movedrelative to the expander to effect setting of the slips.

The device A is particularly useful with well packers or other welltools in which a J-slot connection is employed and wherein it isdesirable to hold one part stationary while allowing movement of anotherpart of said tool. However, it is also applicable for use as a pipeanchor and in FIGURE 8 such an application is shown. In thismodification the device A comprises a central tubular sleeve element 120which is lformed integral with an upper coupling 124 and a lowercoupling 121. The gripping elements or shoes 30 are mounted between thecouplings 124 and 121 in the manner hereinbefore described. The centralsupport or sleeve 120 is formed with the projections 38 (not shown). Thepipe or tubing i112, which is to be anchored, is connected to thecouplings 121 and 124.

The operation of this modification is substantially as heretoforedescribed. 'Ihe device A is connected in the pipe 112 in the mannershown, is lowered to position and at this time the gripping elements 30are engaging the wall of the casing C with a light frictionalengagement. By imparting a rotation to the sleeve 120, the 'camprojections thereon move with respect to the cam surfaces of the shoes30, said shoes being maintained stationary by the frictional contactwith the pipe wall. Through the cam action, as heretofore described, theshoes are moved radially outwardly into tight gripping position with thecasing -wa-ll and so long as the cam projections are engaged with thecam surfaces, the pipe is anchored within the casing. It is noted thatthe provision of the inclined surfaces 36 and 37 make it possible to setthe gripping shoes 30 into tight contact with the casing by either rightor left hand rotation of the sleeve of the assembly A. In the `case ofright hand rotation, the cam projection 38 engages the inclined surface37 of each shoe as shown in FIGURE 7; however, in the case of left handrotation, the projection 38 would engage the surface 36. lIn eitherevent the shoe 30 is caused to undergo a rocking motion along acircumferential path which results in a radially outward movementsuiiicient to obtain the tight gripping contact between the shoe and thepipe Wall.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimsWithout departing from the spirit of the invention.

What I claim is:

l. A gripping device for anchoring a member against movement within apipe including,

a sleeve adapted to be connected with the member,

a pair of gripping elements mounted on said sleeve for limitedrotational movement between said elements and said sleeve,

each gripping element having a non-gripping surface and a grippingsurface spaced circumferentially and radially inward therefrom fornonengagement with the wall of said pipe when said non-gripping surfaceis in engagement with said wall,

each gripping element having extremities adjacent the extremities of theother gripping element,

means mounting said gripping elements for radial movement with respectto the sleeve,

resilient means disposed between the adjacent extremities of saidelements acting upon the elements and constantly urging said elementsoutwardly so that the non-gripping surface of each element is urged intolight frictional engagement with the pipe,

the gripping surfaces of the elements being normally disengaged fromsaid pipe,

and coacting means on the sleeve and on each gripping element,

said coacting means engaging each other when the sleeve is rotated withrespect to said elements to move the gripping surfaces of the grippingelements into tight engagement with the wall of the pipe.

2. A gripping device as set forth in claim 1 wherein,

the gripping surface on each element comprises gripping teeth which arefirmly engageable with' the wall of the pipe when said gripping surfacesof said elements are urged into tight engagement with said pipe Walls.

3. A gripping device as set forth in claim 1 wherein,

the coacting means comprises cam-type projections on the sleeve and camsurfaces on the interior of the gripping elements whereby engagement ofsaid projections with said surfaces effects movement of the grippingelements.

4. A gripping device for anchoring a member against movement within apipe including,

a support adapted to be connected with the member which is to beanchored,

a pair of generally semi-circular gripping elements encircling thesupport and mounted thereon for limited rotational movement relativethereto,

each element having a non-gripping area and a gripping surface spacedcircumferentially and radially inward therefrom, for non-engagement withthe wall of said pipe when said non-gripping area is in engagement withsaid wall whereby each of said gripping elements may pivot about itsnon-gripping area to move said gripping surface into engagement withsaid wall,

means mounting said elements for limited movement in a directionradially of the support,

resilient means interposed between adjacent ends of the grippingelements for normally urging said elements outwardly so that saidnon-gripping area of each element is in relatively light frictionalcontact with the wall of the pipe bore,

and coacting means on the support and on the inner surfaces of thegripping elements,

said coacting means being engageable with each other when the support isrotated relative to the gripping elements to impart a circumferentialrocking movement to said elements to urge said gripping surface of saidelements into tight anchoring engagement with the wall of the pipe.

5. A gripping device as set forth in claim 4, wherein the coacting meansbetween the support and each gripping element comprises a cam-typeprojection and cam-type surface, one on said support and one on saidelement.

6. A gripping device for anchoring a member against movement within apipe including,

a support adapted to be connected with the member,

a gripping element carried by the support and mounted on the exteriorthereof for limited rotational movement relative thereto,

said gripping element having a non-gripping area and a gripping surfacespaced circumferentially and radially inward therefrom fornon-engagement with the wall of said pipe when said non-gripping area isin engagement with said wall whereby each of said gripping elements maypivot about its non-gripping area to move said gripping surface intoengagement with said wall,

means mounting said gripping element for radial movement relative to thesupport,

resilient means normally urging the gripping element outwardly so thatsaid non-gripping area of said element is in light frictional contactwith the wall of the pipe,

and coacting means on the support and on the gripping element,

said coacting means being engageable with each other when the support isrotated relative to the element to impart a rocking motion to thegripping element to thereby move said gripping surface of said elementinto tight gripping engagement with the pipe wall.

7. VA gripping device as set forth in claim 6 wherein the coacting meanscomprises a cam-type projection and a cam-type surface, Yone on thesupport and the other on the gripping element.

8. The combination with a Well packer having anchoring means whichcomprises wall-engaging members and `an expander which is movablerelative to said members to expand the same, of a gripping deviceassociated with said anchoring means,

.said gripping device including a support,

means connecting lsaid support to one of said wallengaging members 4andsaid expander of said anchoring means,

a gripping element carried by the support and mounted for limitedrotational movement relative thereto and for movement in a -radialdirection with respect thereto,

said gripping element having a non-gripping surface and a grippingsurface 4spaced circumferentially and radially inward from saidnon-gripping surface and from the surface of the pipe wall whereby saidelement may undergo limited rocking movement in a circumferentialdirection to engage said gripping surface with said surface of the pipewall,

resilient means normally urging the gripping element outwardly so thatsaid non-gripping surface of said element is in light frictional contactwith the Wall of the well bore into which the packer is lowered,

and coacting means on the support and said gripping element,

said coacting means being engageable upon rotation of the supportrelative to the gripping element to impart a rocking motion to theelement to move said gripping surface of said element into firmengagement with the bore wall and thereby anchor that one of saidWall-engaging members and said expander of the anchoring means to whichthe support is connected against movement in the well.

9. In a well packer, an anchoring means comprising gripping slips and anexpander movable relative to the slips to expand the same intoengagement with the wall of a well pipe into which the packer islowered.

a gripping device below the anchoring means and including a support,

means connecting said support to one of said gripping -slips or saidexpander of said anchoring means,

a plurality of segmental gripping elements carried by the support andmounted for limited rotational movement between said gripping elementsand said support and for movement in a radial direction relative to thesupport,

each of said gripping elements having a non-gripping surface and agripping surface spaced circumferentially and radially inward from saidnon-gripping surface whereby said elements may undergo limited rockingmovement in a circumferential direction about said non-gripping surface,

means for normally urging each of the gripping elements outwardly Isothatsaid non-gripping surface of each element is in light frictionalcontact with the wall of the Well pipe,

and coacting means on said support and said gripping elements,

said coacting means being engageable upon rotation of the supportrelative to said elements to impart a rocking motion to the elements tomove said gripping surfaces of said elements into firm grippingengagement with the pipe wall to thereby hold the lsupport and connectedone of said gripping slips or expander of the anchoring means againstmovement within the well pipe.

l0. In a well packer, the combination as set forth in claim 9 whereinthe coacting means comprises cam-type projections on the support landinclined surfaces on said gripping elements. n i

1l. A gripping device for anchoring a member within a well boreincluding,

a mandrel -connected with the member,

a gripping element mounted upon the mandrel for movement outwardly incontact with the wall of the well and mounted for limited rotationalmovement whereby the mandrel may be rotated with respect to the element,

said gripping element having a non-gripping `surface and a igrippingsurface spaced circumferentially and radially inward therefrom fornon-engagement with the Wall of the well bore when said non-grippingsurface is in engagement with said Wall,

means urging said gripping element radially outward so that thenon-gripping surface of said element is in light frictional contact withsaid wall,

and coacting means on said mandrel `and said gripping element engageablewith each other when the mandIel is rotated with respect to the elementfor urging the gripping surface of said element into tight frictionalengagement with the wall of the bore to thereby anchor said mandrel andmember therein.

12. A gripping `device as set forth in claim 1l wherein =and coactingmeans on said mandrel and said gripping element engageable with eachother when the mandrel is rotated with respect to the element for urgingthe `gripping surface of said element into tight frictional engagementwith the wall of the bore to thereby anchor said mandrel and membertherein.

15. A gripping device for anchoring a member against movement with apipe including,

'a support adapted to be connected with the member,

a gripping element carried by the support -for limited rotationalmovement relative thereto,

said gripping element having a non-gripping surface and a -grippingsurface spaced -circumferentially land radially inward therefrom fornon-engagement with said pipe when said non-gripping surface is inengagement with said pipe,

means mounting said gripping element for radial movement relative to thesupport,

resilient means normally urging the gripping element in such a directionso that said non-gripping surface is urged into light frictional contactwith the wall of the pipe,

and `coacting means on the support and on the gripping ele-ment,

-said coacting means being engageable with each other when the supportis rotated relative to the element to move the gripping surface of saidelement into tight engagement with the pipe wall.

16. A gripping device `as set forth in claim 15 wherein the grippingsurface of the gripping element comprises gripping teeth,

which teeth are firmly engageable with the wall of the pipe when saidgripping surface of said element is urged into tight engagement withsaid pipe wall.

17. A gripping device as set forth in claim 15 wherein the coactingmeans comprises a cam-type projection and a cam-type surface,

one on the lsupport fand the other on the gripping element.

the gripping surface of the gripping element comprises gripping teeth,which teeth are iirmly engageable with the wall of the pipe when saidgripping surface is urged into tight engagement with `said pipe wall.

13. A gripping device as set forth in claim 11 wherein the coactingmeans on said mandrel and said gripping element comprise a cam-typeprojection on one of said mandrel or said gripping element and a4coacti-ng surface on the other of said mandrel or said grippingelement.

14. A gripping device for anchoring a member within a well boreincluding,

ya mandrel connected with the member,

a gripping element mounted upon the mandrel for movement outwardly intocontact with the wall of the Well and also mounted upon the mandrel forrotational movement relative thereto,

`said element having a non-gripping surface `and a `gripping surfacespaced circumferentially and radial ly inward therefrom fornon-engagement with said References Cited in the ile of this patentUNITED STATES PATENTS able contact with said Wall,

14. A GRIPPING DEVICE FOR ANCHORING A MEMBER WITHIN A WELL BOREINCLUDING, A MANDREL CONNECTED WITH THE MEMBER, A GRIPPING ELEMENTMOUNTED UPON THE MANDREL FOR MOVEMENT OUTWARDLY INTO CONTACT WITH THEWALL OF THE WELL AND ALSO MOUNTED UPON THE MANDREL FOR ROTATIONALMOVEMENT RELATIVE THERETO, SAID ELEMENT HAVING A NON-GRIPPING SURFACEAND A GRIPPING SURFACE SPACED CIRCUMFERENTIALLY AND RADIALLY INWARDTHEREFROM FOR NON-ENGAGEMENT WITH SAID WALL WHEN SAID NON-GRIPPINGSURFACE IS IN ENGAGEMENT WITH SAID WALL, MEANS NORMALLY URGING SAIDGRIPPING ELEMENT RADIALLY OUTWARD SO THAT SAID NON-GRIPPING SURFACE ISIN SLIDABLE CONTACT WITH SAID WALL, AND COACTING MEANS ON SAID MANDRELAND SAID GRIPPING ELEMENT ENGAGEABLE WITH EACH OTHER WHEN THE MANDREL ISROTATED WITH RESPECT TO THE ELEMENT FOR URGING THE GRIPPING SURFACE OFSAID ELEMENT INTO TIGHT FRICTIONAL ENGAGEMENT WITH THE WALL OF THE BORETO THEREBY ANCHOR SAID MANDREL AND MEMBER THEREIN.